[PATCH 2/3] pci: pcie-designware: add support for external MSI controller
From: Thomas Petazzoni <hidden>
Date: 2016-08-30 12:57:09
Also in:
linux-devicetree, linux-pci
Subsystem:
pci subsystem, the rest · Maintainers:
Bjorn Helgaas, Linus Torvalds
The Designware PCIe controllers have a built-in MSI controller, which is
already supported by the existing. However, in some situations, it might
be a better choice to use an external MSI controller, especially when it
provides a higher number of MSI interrupts than the built-in one.
Therefore, this commit extends the pcie-designware driver to support the
"msi-parent" DT property, already used by other drivers. It contains a
phandle pointing to the external MSI controller to be used.
Following this commit, the pcie-designware code supports three
possibilities, in this order:
1. If msi-parent is provided, then the MSI controller pointed by this
property is used.
2. Otherwise, and if no ->msi_host_init() function is provided by the
platform-specific "glue", then the built-in MSI controller of the
Designware controller is used.
3. Otherwise, the ->msi_host_init() function of the platform-specific
"glue" is used to do some additional initialization, but it's still
the built-in MSI controller that is used.
Signed-off-by: Thomas Petazzoni <redacted>
---
drivers/pci/host/pcie-designware.c | 24 ++++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)
diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
index 12afce1..1e18a85 100644
--- a/drivers/pci/host/pcie-designware.c
+++ b/drivers/pci/host/pcie-designware.c@@ -437,6 +437,7 @@ int dw_pcie_host_init(struct pcie_port *pp) int i, ret; LIST_HEAD(res); struct resource_entry *win; + struct msi_controller *msi = NULL; cfg_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "config"); if (cfg_res) {
@@ -525,10 +526,21 @@ int dw_pcie_host_init(struct pcie_port *pp) pp->lanes = 0; if (IS_ENABLED(CONFIG_PCI_MSI)) { - if (!pp->ops->msi_host_init) { + if (of_find_property(pp->dev->of_node, "msi-parent", NULL)) { + struct device_node *msi_node; + + msi_node = of_parse_phandle(pp->dev->of_node, + "msi-parent", 0); + if (!msi_node) + return -ENODEV; + + msi = of_pci_find_msi_chip_by_node(msi_node); + } else if (!pp->ops->msi_host_init) { + msi = &dw_pcie_msi_chip; + msi->dev = pp->dev; pp->irq_domain = irq_domain_add_linear(pp->dev->of_node, MAX_MSI_IRQS, &msi_domain_ops, - &dw_pcie_msi_chip); + msi); if (!pp->irq_domain) { dev_err(pp->dev, "irq domain init failed\n"); ret = -ENXIO;
@@ -538,7 +550,9 @@ int dw_pcie_host_init(struct pcie_port *pp) for (i = 0; i < MAX_MSI_IRQS; i++) irq_create_mapping(pp->irq_domain, i); } else { - ret = pp->ops->msi_host_init(pp, &dw_pcie_msi_chip); + msi = &dw_pcie_msi_chip; + msi->dev = pp->dev; + ret = pp->ops->msi_host_init(pp, msi); if (ret < 0) goto error; }
@@ -550,9 +564,7 @@ int dw_pcie_host_init(struct pcie_port *pp) pp->root_bus_nr = pp->busn->start; if (IS_ENABLED(CONFIG_PCI_MSI)) { bus = pci_scan_root_bus_msi(pp->dev, pp->root_bus_nr, - &dw_pcie_ops, pp, &res, - &dw_pcie_msi_chip); - dw_pcie_msi_chip.dev = pp->dev; + &dw_pcie_ops, pp, &res, msi); } else bus = pci_scan_root_bus(pp->dev, pp->root_bus_nr, &dw_pcie_ops, pp, &res);
--
2.7.4